Drill-bit die



Dec. 26, 1922. 1,440,018 F. J. LAIRD.

DRILL BIT DIE. FILED JULYW, 1920'.

Patented Den 26, i922 resin: :1". rattan, or racist-cane.

Darrin-err 'nrn.

Application filed July 17,

To all 10/ 60777, it may concern.

Be it known that l. liurrrr: citizen of the United States. residii Butte, in the county oil? Elilver ll and i v of ilflontana, have invented certain new and useful improvements in Drill-Bit Dies, of which the follmving is a specification.

The present invention relates to sharpeners and more particularly to a new and useful improvement in clamping dies for use in Leyner, Sullivan, l l augh or other types of drill-sharpening machines.

it is the principal object or the invention to make provisions wl'icreliiy a drill bit may be iin'shed in the clamping die instead of in. an outside gauging block or ilorming die as has been the prevailing practice.

Another object is die mechanism whereby the amount of high carbon steel material necessary for making bits for v r ous types oi? drill steel is reduced to a small amount and whereby the split clamping die, which weighs about twenty to thi'ty-live pounds, may be made of a poorer grade of steel, whether hardened or not.

Various other objects will appear from the description in connection withthe accompanying drawings in which Fig. l is a sectional view or a die embodying the invention;

Fig. 2 is an end view thereof;

l 3 is an elevation oi? a modified tlorm oi? split bushing, one of the halves only being shown; and

Fig. a is an end view of the complete bushing.

In the drawings 1 represents a split die which may be made of any suitable low priced material and 2 represents a split bushing of high grade materiah preferably high carbon tool steel.

The end 3 ot' the bushing is of such proportions as to effectively withstand the heavy thrust upon it and bearing against a shoulder 41 in the die. The busningalso has a beveled shoulder 5 seated in a similarly shaped recess 6 in the die so that the bushing- 2 is held in position in the die when the bottom and top parts are separated to insert the steel to be sharpened or to remove the sharpened steel from it. The clamping face 8 of the bushing terms a continuation of the clamping face 7 of the die 1.

The principal feature with which this invention is identified is the double taper com d. LAIRD. a

drill 1920. Serial No. 397,035.

the

prising the inner taper 9 and outer smaller taper 1.0.

rate gaging die and giving the required outside taper. I In the present instance, the double taper is made in a single operation,

taper at the same time. The hit can in this manner he finished more accurately and per-- 'l'ectly than in the gage block in that the line of intersection between the outer and the inner taper will ,be placed accurately for every drill sharpened.

- A difierent bushing will be required for each size or" bit. Since the bushing however is oi? small size compared with the die, the expense is correspondingly reduced.

The devic thus has the advantage to permit the renewing of a relatively small part in place of the large expensive die, to make a drill bit to the required by changing bushings for each gage to keep the steel in plain sight of the operator, to prevent overtravelling of dolliesreducing breakage and Wear of both dollies and springs-, to make the gaging of bits mechanical instead of leaving it to the skill and judgment of: the operator, to improve the steel. sh arpening standard and to get longer service from the dies.

In Fig. a the outer taper oi"; the bushing 12 has eccentric arcs 13 to make a double taper bit with clearance on the cutting corners.

In forming a double taper bit, it is essential to have not only cutting faces but also reaming edges. These edges must have the same diameter as the taceot the bit and also must have clearance. This is accomplished by arcs radiating from points equally spaced oil the center, Separate bushings may be used to. place the clearance on the proper edge for right hand or left hand rotation.

I claim:

1. For use in drill-sharpening machines, an axially split die having a removable split bushing constituting the forming element and means on the die and the bushing afiording a self-centering interlocking engagement.

The stock is driven backinto the die for i the double 2. Aryangc 4L Arrangement according to claim 3 in WhlCh the outer taper has eccentrlc surfaces afi'ordmg clearance on the outer cuttlng corners of the 101*; formed thereby.

In testlmony whereof, I affix my slgnu- L cure.

FRANK J. LAIRD. 

